Yamaha PSR-9000 Owner's Manual - Page 144

MIDI Functions Built into the rear panel of the PSR-9000 are two standard sets to MIDI terminals (MIDI IN A/B, MIDI OUT A/B), a TO HOST terminal, and a HOST SELECT switch. The MIDI Functions give you a comprehensive, powerful set of tools for expanding your music recording and performance possibilities. This section explains what MIDI is, and what it can do, as well as how you can use MIDI on your PSR9000. What's MIDI? No doubt you have heard the terms "acoustic instrument" and "digital instrument." In the world today, these are the two main categories of instruments. Let's consider an acoustic piano and a classical guitar as representative acoustic instruments. They are easy to understand. With the piano, you strike a key, and a hammer inside hits some strings and plays a note. With the guitar, you directly pluck a string and the note sounds. But how does a digital instrument go about playing a note? q Acoustic guitar note production q Digital instrument note production L Sampling Tone Generator (Electric circuit) R Sampling Note Note Playing the keyboard Pluck a string and the body resonates the sound. Based on playing information from the keyboard, a sampling note stored in the tone generator is played through the speakers. As shown in the illustration above, in an electronic instrument the sampling note (previously recorded note) stored in the tone generator section (electronic circuit) is played based on information received from the keyboard. So then what is the information from the keyboard that becomes the basis for note production? For example, let's say you play a "C" quarter note using the grand piano sound on the PSR-9000 keyboard. Unlike an acoustic instrument that puts out a resonated note, the electronic instrument puts out information from the keyboard such as "with what voice," "with which key," "about how strong," "when was it pressed" and "when was it released." Then each piece of information is changed into a number value and sent to the tone generator. Using these numbers as a basis, the tone generator plays the stored sampling note. q Example of Keyboard Information Voice number (with what voice) Note number (with which key) Note on (when was it pressed) and note off (when was it released) Velocity (about how strong) 01 (grand piano) 60 (C3) Timing expressed numerically (quarter note) 120 (strong) MIDI is an acronym that stands for Musical Instrument Digital Interface, which allows electronic musical instruments to communicate with each other, by sending and receiving compatible Note, Control Change, Program Change and various other types of MIDI data, or messages. The PSR-9000 can control a MIDI device by transmitting note related data and various types of controller data. The PSR-9000 can be controlled by the incoming MIDI messages which automatically determine tone generator mode, select MIDI channels, voices and effects, change parameter values and of course play the voices specified for the various parts. MIDI messages can be divided into two groups: Channel messages and System messages. Below is an explanation of the various types of MIDI messages which the PSR-9000 can receive/transmit. 144 Reference q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q 142